The CRS is a Congressional "think tank" with a staff of around 700. Reports are commissioned by members of Congress on topics relevant to current political events. Despite CRS costs to the tax payer of over $100M a year, its electronic archives are, as a matter of policy, not made available to the public.

Individual members of Congress will release specific CRS reports if they believe it to assist them politically, but CRS archives as a whole are firewalled from public access.

This report was obtained by Wikileaks staff from CRS computers accessible only from Congressional offices.

Electric utility generating facilities are a major source of air pollution. The combustion of fossil fuels (petroleum, natural gas, and coal), which accounts for about two-thirds of U.S. electricity generation, results in the emission of a stream of gases. These gases include several pollutants that directly pose risks to human health and welfare, including particulate matter (PM), sulfur dioxide (SO2), nitrogen oxides (NOx), and mercury (Hg). Particulate matter, SO2, and NOx are currently regulated under the Clean Air Act (CAA), and the Environmental Protection Agency (EPA) has promulgated rules to regulate mercury beginning in 2010. Other gases may pose indirect risks, notably carbon dioxide (CO2), which may contribute to global warming. Table 1 provides estimates of SO2, NOx, and CO2 emissions from electric generating facilities. Annual emissions of Hg from utility facilities are more uncertain; current estimates indicate about 48 tons. Utilities are subject to an array of environmental regulations, which affect in different ways both the cost of operating existing generating facilities and the cost of constructing new ones.